How come strokes are deadly?

Without going into extreme detail, strokes are most commonly caused by a burst in blood vessels due to blockage in turn leaking blood into the brain. strokes are extremely dangerous because blood in the brain can sometimes lead to dangerous conditions such as hydrocephalus, increased intracranial pressure, and dangerous blood vessel spasms. If not treated aggressively, these conditions can lead to severe brain damage, brain herniation, and even death. This is why even minor episodes of bleeding inside the brain require emergency evaluation by a neurosurgeon.

The short version is that a stroke deprives the brain of blood. Either an artery (or a tiny artiole) bursts, or more often, is blocked by a clot, and then the blood cannot flow to that part of the brain.

Yes, there may be blood floating around the brain but every single cell needs to have constant access to fresh blood and you don't get that from a hemorrhage.

And they are not always lethal - about 1/3 have total recovery, 1/3 recover with disabilities and 1/3 expire.

First of all take a few deep breathes! Just relax I assume you are young - middle aged from the way you are writting. At this age the risk of suffering heart attack, stroke and diseases resulting in death is extremly low as the body is resiliant and able to rejuvinate itself it it becomes injured. As we get older this ability to self repair slows, increasing disease risk. You've stated that you have have a blood test which is normal. This is good! Keep a healthy and active lifstyle now and you can prolong the ageing process, and inturn death. Don't sweat the small stuff, it only causes lapses in the immune system! Healthy eatting, exercise, laughter and family all ensure a long, healthy life! Don't stress about death! Enjoy the life you currently have and deal with each day and its hurdles as it comes!!! You only love once!